Filter materials and filters made therefrom

Patent metadata

Field	Value
Publication number	US-2017156393-A1
Application number	US-201515129988-A
Country	US
Kind code	A1
Filing date	Mar 27, 2015
Priority date	Mar 31, 2014
Publication date	Jun 8, 2017
Grant date	—

Abstract

The present invention relates to filter material for inclusion in a smoking article, wherein the filter material is in the form of a fibrous tow or a non-woven sheet comprising fine cellulose acetate fibres having a mean diameter of from about 1 μm to about 15 um. The invention also relates to processes for preparing filter material for inclusion in a smoking article, the filter material comprising fine cellulose acetate fibres having a mean diameter of from about 1 μm to about 15 μm. The invention further relates to filters or filter elements comprising the filter material, smoking articles comprising the same, and use of the filter material in smoke filtration.

First claim

1 . A filter material for inclusion in a smoking article, wherein the filter material is in the form of a fibrous tow comprising fine cellulose acetate fibres having a mean diameter of from about 1 μm to about 10 μm.

2 . A filter material as claimed in claim 1 , wherein the tow is formed from fibres and at least about 80% by weight of the fibres are fine cellulose acetate fibres.

3 . A filter material as claimed in claim 1 , wherein the fine cellulose acetate fibres have a diameter of no less than 0.3 μm.

4 . A filter material as claimed in claim 1 , wherein the fine cellulose acetate fibres comprise cellulose acetate and an additive.

5 . A filter material as claimed in claim 1 , wherein filter material further comprises a plasticizer which is one or more selected from the group consisting of: triacetin; polyethylene glycol; triethyl citrate; and
triethylene glycol diacetate.

6 . A filter material as claimed in claim 1 , wherein the filter material removes from about 50% to about 90% phenol from tobacco smoke.

7 . A filter material as claimed in claim 1 , wherein the filter material removes from about 50% to about 90% cresol from tobacco smoke.

8 . A process for preparing filter material for inclusion in a smoking article, the filter material comprising fine cellulose acetate fibres having a mean diameter of from about 1 μm to about 10 μm, the process comprising electrospinning or centrifugal spinning or melt spinning.

9 . A process as claimed in claim 8 , wherein a cellulose acetate solution is spun, the solution having a cellulose acetate concentration of from about 6% to about 30%.

10 . A process as claimed in claim 8 , wherein the fine cellulose acetate fibres are produced by spinning through a spinneret using centrifugal force, and the spinneret spins at a rate of from about 4500 to about 7500 rpm.

11 . A process as claimed in claim 8 , wherein the flow rate of the cellulose acetate solution through the orifice(s) of the spinneret is from about 5 to about 100 ml/min.

12 . A process as claimed in claim 8 , wherein the fine cellulose acetate fibres are laid down as a non-woven sheet or non-woven web directly following spinning.

13 . A process as claimed in claim 12 , wherein the fine cellulose acetate fibres are drawn onto a base sheet upon which a non-woven sheet or web is formed by a vacuum pull, by air flow or by electrostatic charge.

14 . A filter material obtained or obtainable by a process as claimed in claim 8 .

15 . A filter element or filter for a smoking article, comprising a filter material as claimed in claim 1 , or comprising a filter material obtained or obtainable by a process for preparing filter material for inclusion in a smoking article, the filter material comprising fine cellulose acetate fibres having a mean diameter of from about 1 μm to about 10 μm, the process comprising electrospinning or centrifugal spinning or melt spinning.

16 . A filter as claimed in claim 15 , wherein the filter has a pressure drop of from about 60 to about 140 mmWG.

17 . A filter as claimed in claim 15 comprising from about 30 to about 90 mg of filter material in the form of a fibrous tow comprising fine cellulose acetate fibres having a mean diameter of from about 1 μm to about 10 μm.

18 . A filter as claimed in claim 17 , comprising from about 40 to about 80 mg of said filter material.

19 . A smoking article comprising a filter or filter element as claimed in claim 15 .

20 . A filter material as claimed in claim 1 configured for filtration of tobacco smoke.

Assignees

• British American Tobacco Investments Ltd

Inventors

• Branton Peter
• Galati Rose
• Grierson Gordon
• SAMPSON John

Classifications

• A24D3/10

  of cellulose or cellulose derivatives · CPC title

• A24D3/063 Primary

  of the fibers · CPC title

• D01D5/04

  Dry spinning methods {(D01D5/0038 takes precedence)} · CPC title